In typical wireless communications two wireless transmit/receive units (WTRUs), Alice and Bob, communicate with each other on a channel. To exclude an illegitimate entity, Eve, Alice and Bob cryptographically protect their communications. Traditional cryptographic techniques, which rely on computational difficulty, are increasingly ineffective as the availability of computing power increases. In addition, an Eve may use a spoofing to disrupt legitimate communications in variety of ways, such as through denial of service or signals by impersonating a legitimate communicating entity.
Information-theoretically secure cryptographic techniques eliminate the reliance on computational difficulty. For example, Alice and Bob may employ the reciprocity of a wireless channel to extract secret keys. These techniques usually rely on exchanging signals, or probing, the wireless channel, such as in a time division duplex (TDD) manner, to collect correlated information from which common secret bits are obtained. During the probing, it may be difficult for Alice and Bob to be sure that the signals they received originated from a legitimate source. Thus a method an apparatus for providing authentication for secure wireless communication would be advantageous.